NEMESIS developed an innovative weighing technology, the EasyWeigh® system, at the state of the art in dynamic weighing sector and installed on all our machines.
EasyWeigh® technology allows to overcome all the problems usually related to the commonly used “peak weight” technology, greatly enhancing the accuracy and the solidity of the checkweighers.
What is the “peak weight” technology?
Most of checkweighers’ manufacturers use the “peak weight” algorithm in their products.
This technology, in brief, measures the weight value at the “peak” part of the signal coming from the load cell.
“Peak weight” technology:
- requires the user to perform laborious and time-wasting operations, as the calibration for each product and the constant check of the machine’s performances. Moreover, when changing the weighted products, various tests and setups are required, including the check of the “zone of indecision” (ZOI) – to confirm the correct operation of the machine – or the reset of the parameters, in order to be sure that the detected conforming weights stay within the predetermined thresholds;
- is badly affected, in its weighing accuracy, by air currents, temperature variation and vibrations;
- requires to find a correction factor to align static and dynamic measurement results;
- gives certified weighing results only for the specific products showed in the machine’s metrological plate (see Fig. 1).
Fig. 1: “Peak weight” metrological plate
No more learning and calibration
Thanks to its innovative algorithm, EasyWeigh® technology allows to weigh every new product shape, format or line orientation without the need of any calibration, learning procedures (for example, weighing 10 samples, editing the dimensions of new product) or any other check (no tests are required to verify that the dynamic weight shown is equal to the static weight – boring and time wasting operation, especially to find the proper correction factor).
The only data to consider are the conveyors maximum linear speed and maximum measurable weight: any object within these limits, regardless of shape, packaging, content and size, can be immediately weighed on the checkweigher.
Just select the new product’s speed, valid weight thresholds and press Start.
An EasyWeigh® system gives certified measurements for every product just having weight and line speed within the machine’s limit, no need for specific allowances on the metrological plate: EasyWeigh® metrological plate (see Fig. 2) only shows those ranges.
Smart load cell
The two existing types of weighing sensors (load cells) used for checkweighers are Electromagnetic load cells and Strain gauge load cells:
- Electromagnetic load cells have good weighing accuracy, but are very fragile and expensive;
- Strain gauge load cells, on the contrary, tend to reach inferior precision levels, but are very sturdy and far more convenient.
NEMESIS EasyWeigh® system bases on strain gauge load cells (very sturdy by themselves), also installing additional strong protections to best prevent any hurting / overload damage all around the cell. This primarily means dramatically reducing the need of load cell replacing, avoiding huge costs of maintenance.
Nonetheless, thanks to our innovative technology, we are able to obtain accuracy performances equal, or even superior, to Electromagnetic load cells.
No need to choose between accuracy and resistance, just get the both.
Reduced products spacing needs
EasyWeigh® system, thanks to its accuracy, allows to get the best performances in a reduced weighing time: that means a smaller gap required between products.
For a correct weighing, only one product has to be on the weighing conveyor at a time.
Line spacing between products can be considered as “gap” or “pitch” (see Fig. 3):
- “Gap” is the space between the rear of a product and the front of the following one;
- “Pitch” is the distance measured from the front of a product and the front of the following one.
Fig. 3: Gap and Pitch definition
“Peak weight” checkweighers need a GAP between products a little greater than the weighing conveyor length (for each product, measurement sampling stops when a photocell detects the products is over the weighing conveyor).
On the contrary, EasyWeigh® checkweighers just need the PITCH between two products to be a little greater than the weighing conveyor length (a shorter sampling time being needed, once the front of a product reach the photocell at the end of the weighing conveyor, the system detects it as “weighing completed”, so the following products can enter the weighing conveyor without the previous one altering its measurement).
The advantage in terms of spacing is clearly explained in the following Fig. 4.
Fig. 4: Example of spacing needs for EasyWeigh® and “Peak weight” technologies
As a result, for a determined line throughput, EasyWeigh® technology allows to use a shorter weighing conveyor, meaning an inferior conveyor speed required. This implies not only a concrete advantage in terms of durability (thanks to the reduced wearing out of the components) but also a greater accuracy.
Two basic examples can help to understand this advantages.
Assume 100 x 250 mm products, with a line throughput of 60 pieces / min and a weighing conveyor length of 315 mm:
- With a “peak weight” technology the conveyor running speed needs to be equal to 35 m/s
- With EasyWeigh® technology it’s sufficient to keep a conveyor running speed equal to 20 m/s
Assume 100 x 250 mm products, with a line throughput of 60 pieces / min, to reach the proper weighing time of a product:
- With a “peak weight” technology the conveyor length has to be equal to 415 mm, having the scale conveyor running at a speed of 26 m/s
- With EasyWeigh® technology the conveyor length has to be equal to 315 mm, having the scale conveyor running at a speed of 20 m/s
A smaller machine, a greener machine
Last but not least, EasyWeigh® system – as shown – allowing the use of shorter conveyors leads to a globally smaller and flexible machine.
This is indeed a very interesting element to consider, in fact a smaller machine has numerous advantages compared to a bigger one:
1. A compact machine is not just space-saving by herself, but – even more important – far easier to integrate in the production line, where space is often a key driver;
2. The smaller the machine, the less its energy consumption: NEMESIS green technology allows up to 80% energy saving to the user (and, for us, up to 50% reduction of energy used for building the systems, being free from heavy mechanical structures);
3. Reduced maintenance costs, thanks to the aforementioned increased durability and the inferior spare parts cost and easier shipping.